The Rodent Models Core is essential to the success of IDDRC projects that use rodent models for the study of normal and abnormal development and degeneration of the nervous system. The Rodent Models Core provides technical support for the generation and characterization of transgenic, knock-out, and knock-in strains of mice, access to sophisticated shared behavioral equipment, and expertise in the behavioral phenotyping of mouse and rat models of IDD and related disorders. The Rodent Models Core was rated outstanding in the review from 2005, while being in the midst of planning for a major renovation and introduction of entirely new services (i.e., behavioral testing). The Core was highly rated for its leadership (This application was written with impressive insights into research needs, and great attention to detail'), planning of the new design (Barrier, non-barrier, and quarantine rooms are now in abundance, with thorough security and thoughtful facility management'), and support for research. However, questions were voiced in two areas: 1) the interim status of the renovation and facility management staffing (the overall summary commented that a degree of uncertainty remains with the Rodent Models Core, since the person who will manage the core has not yet been hired, and the facility is not yet completed') and 2) the prediction that we would have difficulty hiring a PhD level staff member for the behavioral testing service and the mistaken impression that only two investigators would actually make use of the behavioral facility. Five years later, we believe we have successfully met all of our milestones. The renovation was completed with creation of a dedicated suite for behavioral testing, acquisition of major equipment, and upgrade of infrastructure, transforming the RMC into a barrier facility. All staff, including the facility manager and PhD level psychologist for the Behavioral Testing Suite, were hired, trained, and are now stable members of the Waisman IDDRC core staff. The RMC is now an outstanding resource that is central to the scientific programs of 16 IDDRC investigators.